Estimation of Nitrate Contamination of an Agro-Ecosystem Outwash Aquifer Using a Nitrogen Mass-Balance Budget
| Autor: | Timothy K. Cowdery, Jeffrey D. Stoner, Larry J. Puckett, David L. Lorenz |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Hydrology
geography Environmental Engineering geography.geographical_feature_category Denitrification Water table Environmental engineering chemistry.chemical_element Aquifer Management Monitoring Policy and Law engineering.material Pollution Nitrogen Manure chemistry engineering Environmental science DNS root zone Fertilizer Waste Management and Disposal Groundwater Water Science and Technology |
| Zdroj: | Journal of Environmental Quality. 28:2015-2025 |
| ISSN: | 0047-2425 |
| DOI: | 10.2134/jeq1999.00472425002800060043x |
| Popis: | A mass-balance budget of N cycling was developed for an intensive agricultural area in west-central Minnesota to better understand NO 3 contamination of ground water in the Otter Tail outwash aquifer. Fertilizer, biological fixation, atmospheric deposition, and animal feed were the N sources, and crop harvests, animal product exports, volatilization from fertilizer and manure, and denitrification were the N sinks in the model. Excess N, calculated as the difference between the sources and sinks, was assumed to leach to ground water as NO 3 . The budget was developed using ground water data collected throughout the 212-km 2 study area. Denitrification was estimated by adjusting its value so the predicted and measured concentrations of NO 3 in ground water agreed. Although biological fixation was the largest single N source, most was removed when crops were harvested, indicating that inorganic fertilizer was the primary source of N reaching the water table. It was estimated that denitrification removed almost half of the excess NO, that leached below the root zone. Even after accounting for denitrification losses, however, it was concluded that the ground water system was receiving approximately three times as much N as would he expected under background conditions. |
| Databáze: | OpenAIRE |
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